Combination coil supporting and covering apparatus for box annealing furnace



March 1957 A. R. HARDTMAYER, JR

COMBINATION COIL SUPPORTING AND COVERING NACE APPARATUS FOR BOX ANNEALING FUR Filed Nov. 12, 1954 V INVENTOR.

- ALFRED R. HARDTMAYER, J12,

his Aflo rn ey.

United States Alfred R. Hardtmayer, In, Pittsburgh, Pa, assiguor to ynited States Steel Corporation, a corporation of New ersey Application November 12, 1954, Serial No. 468,505

7 Claims. 01. 263-49) The present invention relates to metallurgical annealing equipment and more particularly to improved apparatus for supporting and covering coils in a box annealing furnace.

Somesteels, for example, those grades of silicon steel which contain in excess of 3.00% silicon, require high temperature box annealing in coiled form at steel temperatures exceeding 2000 F. At these temperatures the structural strength of the steel is greatly impaired so that the coil may be easily distorted. As a result of such impairment, the customary annealing practice, wherein one coil is superimposed on another with a circulation separator between, cannot be utilized due to the physical damage and distortion of the bottom coil of-the stack brought about by the weight of the stack or coil .above it. I propose a combination coil supporting and covering apparatus which provides independent supporting and covering means for each individual coil in a stack of coils on the base of a box annealing furnace.

It is, accordingly, an object of my invention to provide apparatus for supporting and covering coils in a box annealing furnace wherein each coil in a stack on the-same furnace base is supported and covered independently of any other coil in the stack. 1

This and other objects will become more apparent after referring to the following specification and attached drawings, in which:

Figure 1 is a top plan view;

.Figure 2 is a vertical sectional view taken on the line II-II of Figure 1; and r Figure 3 is a cross-sectional view taken on the line III-III of -Figure 2.

Referring more particularly to the drawings, reference numeral 2 designates an annular refractory supporting base in the bottom of a metallurgical box annealing furnace which is provided with an upper portion 4 of reduced diameter and a circumferential flange 6 forming a continuous trough 8 around the periphery of the base. The base 2 may be provided with a center opening 10 and an atmosphere circulating fan 12 installed therein where it is desired that the annealing process be conducted in a gaseous atmosphere to obtain desired metallurgical properties in the material to be annealed. An annular intermediatesupport 14 rests on the base 2 and carries a heavy annular lower hearth plate 16 which is provided with a center opening 18 aligned with the fan 12. The intermediate support 14 is of lesser diameter than the base 2 and is made up of a plurality of vertical baffle plates 19 arranged in spaced-apart relation around the center opening 10 and fan 12. The upper portion of the opening 18 in the lower hearth plate 16 is of greater cross-sectional area than the lower portion so as to provide a shoulder 20 around the inner circumference of the plate. A coil C of metal strip to be annealed is supported on the lower hearth plate with its core coincident with the enlarged diameter portion of the opening 18.

An inner tubular column 22 having an open bottom 2,784,957 Iatented Mar. 12, 1957 rests loosely on the shoulder therefrom through the core of the coil C. The top of the column 22 is partially sealed by an orifice plate 26. The column is also provided with openings 28 through the wall thereof intermediate its height. The function of the orifice plate 26 is to restrict the flow of atmosphere gas through the top of the column and consequently cause a portion of the fan discharge to flow through the openings 28.

A combination coil support and inner cover enclosure 30 is disposed over the coil C and the lower hearth plate 16 with its bottom edge resting in the trough 8. The combination support and cover 30 is a cylindrically formed enclosure, which may be cast, welded or similarly formed with either straight or corrugated side walls.

The top of the support cover enclosure is an integral part and form a heavy upper hearth plate 32 which is provided with a center opening 34 for receiving the projecting end of the column 22. A series of support ribs 36 are spaced about the inner circumference of the enclosure to lend strength and rigidity thereto. Each of the ribs extends laterally along the underside of the upper hearth plate 32 and thence downwardly along the full length of the side wall, as best shown in Figures 1 and 2. The structural rigidity of the enclosure is strengthened by a plurality of support arms 38 which are attached to and extend radially from the column 22 in a plane immediately below the upper plate 32. A binder ring 40 may be attached circumferentially around the lower edge of the enclosure to help prevent possible distortion of the side walls. The upper surface of the upper plate 32 is providedwith an open top channel 42 extending therearound adjacent its outer edge. The plate 32 is also provided with a plurality of vertical passages 44 which permit circulation of atmosphere gases.

A coil C" is supported on the upper hearth plate 32 with its core aligned with the center opening 34 of the plate 32 and its body surrounding the portion of the column 22 which projects upwardly from the hearth plate 32 to extend approximately mid-way into the core of the coil. r

The upper portion of the column 22 is thus adapted to be utilized as both a coil positioning guide and stack stabilizer.

A cylindrically shaped enclosure 46, with either straight or corrugated side walls, is disposed over the coil C" with the bottom edges of its side walls resting in the channel 42.

The channel 42 as well as the trough 8 are provided for sealing purposes to prevent escape of atmospheric gas from the enclosures 46 and 3%), respectively. The passages 44 in the upper hearth plate 32 permit the flow of atmospheric gas from the interior of the lower enclosure 30 to the interior of the upper enclosure 46.

Column 22 is dimensioned to fit into the eye of the coil C and to permit the lowering of coil C" over its upper portion with a minimum of manipulation by the crane operator. Both the enclosures 30 and 46 are of sufiicient size to accommodate the largest diameter coil of the greatest width of strip to be annealed and at the same time provide sufiicient space above the coils and beyond the coil faces to permit circulation of the atmospheric gas.

Should use of the column 22 not be desired for any reason, it may be removed and the remaining elements of the apparatus used with only minor modifications for strength purposes depending on the weight: of coils being annealed.

The invention thus provides combination supporting and covering means which brings about improved structural rigidity and stability by transferring the superimposed load of the stack to the base of the furnace through 20 and projects upwardly the walls" and reinforcing ribs of the lower enclosure. In addition, the tubular column 22 of the invention provides stack stabilizing and coil positioning means.

' Whileqone embodiment of my invention; has. been jecting upwardly fromv said hearth, plateand extending;

througlrthecenter opening in thetop, of said first rigid enclosure, radially. extending supporting means carried by' said. column inengagement with the undersurface-of the top of. said enclosure adjacent said center opening for supporting. the-mid-portion of said top, and a second rigid. enclosure'having a top, side Walls and open bottom removably disposed on the top of said first enclosure.

2. Combination coil support and inner cover apparatus as. defined by claim 1 characterized by said hollow column having openings in thewalls and in at least one end thereof for conducting atmosphere therethrough, and the top of said first enclosure having at least one hole therethrough in addition to said center opening communicating with the'interior of said second enclosure for conducting atmosphere from the interior of said first enclosure tothe interior of said second enclosure.

3. Combination coil support and innercover apparatus as defined by claim 1 characterized by said base including, a continuous trough extending peripherally adjacent its edge for receiving the bottoms of the side walls, of said first enclosure, and a binder ring attached to and extending around the side wall portions of said first enclosure resting in said trough for stabilizing said side walls.

4. Combination coil support and inner cover appara: tus for. a box annealing furnace as defined by claim 1 characterized, by said first enclosure having a plurality of spaced-apart stabilizing ribs on the interior thereof each extending laterally along a portion of the underside of the, enclosure top and thence downwardly along the side wall.

5. Combination coil support and inner cover, apparav tusfor a box annealing furnace havingv arbase with a central opening therein which, comprises a. lower hearth plate havinga center opening therethrough supported on said base with its center opening communicating with the central opening in said base, a hollow column having a restricted opening in its top and an open bottom removably disposed on said lower hearth plate over said center opening and projecting upwardly therefrom, radiallyextending supporting means carried by said coleumnintermediate its length and spacedrabove said lower hearth plate a distance exceeding the height of; acoil, said column having at least one opening through the wall thereof below said supporting means, a first rigidenclosure having a top with a center opening, sidewalls and an open bottom removably disposed on said base over said column with the. upper portion of the latter projecting upwardly throughthe center opening in said top, said base including a continuous trough extending peripherally adjacent its edge for receiving the bottoms of said side walls, said enclosure top being supported; on

said supporting means, a continuousopen top channel on the upper surface of said enclosure top extending;

peripherally adjacent its edge, and a second rigid enclo sure having a top, side walls and open bottom removably disposed on the top of said first enclosure with the bottoms oflthe side walls thereof resting-in said open top channel, said first enclosure top having at least one hole therethrough communicating; with the interior of, said.

second enclosure for conducting atmosphere from theinterior of said first enclosure to the interior of said. second enclosure.

6. Combination coil support and inner cover apparatus for a box annealing furnace as defined by claimjjl including a binder ring attached to and extendingaround the side wall portions of said first enclosure resting in said troughforstabilizing said sidewalls.

7. Combination coil support and inner cover appara tusfor a boX annealing furnace as defined by claim,5,.

characterized by said firstenclosure having a plurality of spaced-apart stabilizing ribs on the interior thereof. each extending laterally along a portion of thejunderside;

of the enclosure top and thence downwardly along the-- side wall.

References. Cited in the file, of this patent UNITED STATES PATENTS 

